This research will provide new, fundamental information concerning chemical communication in a primate species. The overall, long range objectives are to define the chemical nature and behavioral significance of the scent marks utilized by the South American tamarin, Saguinus fuscicollis, a member of the marmoset family (Callitrichidae), in social and sexual communication. The scent marks of these primates encode messages on identify of species, subspecies, and individual as well as information relating to sexual and social status. Scent mark material, a mixture of gland secretion, some urine and possibly genital discharge, is chemically complex and includes esters, acids, alcohols, aldehydes and hydrocarbons. To date our analytical studies using high resolution capillary gas chromatography have not revealed any qualitative differences in the scent marks of animals which differ in their sex, subspecies or species. Therefore, we have embarked on a study to evaluate quantitative differences in the scent mark constituents. Studies are proposed to identify the concentration profiles of the components which define gender, subspecies and species. Analysis by computerized pattern recognition techniques will target those components which are correlated with gender, subspecies and species. Sophisticated GC/MS/DS instrumentation will then be employed as the major tool for identification and quantitation of the targeted components. Their role in chemical communication will be tested by behavioral assay. Bacterial studies will also be undertaken to establish the role of microbial action in the production of some of the highly volatile components. Finally, studies aimed at the identification of previously unknown components of lower volatility will be carried out. We anticipate that this research will eventually lead to a deciphering of the chemical code such that in the end it will be possible to reconstruct with synthetic formulations the wide variety of communicatory signals employed by the tamarins. To accomplish this goal a unique interdisciplinary research team consisting of two organic chemists, a primatologist and a bacteriologist has been assembled at the Monell Chemical Senses Center. These studies follow logically from prior work of our laboratory. To the best of our knowledge this research program, involving the very close collaboration of chemists, primatologists and bacteriologists to explore and define a chemical communication system in a primate species, is unique in the United States.